{"id":"CVE-2021-31520","aliases":["EUVD-2021-18420","GHSA-f4cv-895p-vw62"],"status":"published","title":"A weak session token authentication bypass vulnerability in Trend Micro IM Security 1.6 and 1.6.5...","description":"A weak session token authentication bypass vulnerability in Trend Micro IM Security 1.6 and 1.6.5 could allow an remote attacker to guess currently logged-in administrators' session session token in order to gain access to the product's web management interface.","severity":{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-12","score":0.03901,"percentile":0.90415,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-287"],"published":"2021-05-10T11:00:31Z","modified":"2026-06-17T03:51:57Z","products":[{"vendor":"trend micro","product":"trend micro im security"},{"vendor":"trendmicro","product":"im_security"}],"references":[{"url":"https://success.trendmicro.com/solution/000286439","tags":["x_refsource_MISC","x_transferred","Patch","Vendor Advisory"]},{"url":"https://www.zerodayinitiative.com/advisories/ZDI-21-525/","tags":["x_refsource_MISC","x_transferred","Third Party Advisory","VDB Entry"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-31520"},{"url":"https://github.com/advisories/GHSA-f4cv-895p-vw62"}],"sources":{"cve":[{"id":"CVE-2021-31520","description":"A weak session token authentication bypass vulnerability in Trend Micro IM Security 1.6 and 1.6.5 could allow an remote attacker to guess currently logged-in administrators' session session token in order to gain access to the product's web management interface.","status":"published","published":"2021-05-10T11:00:31Z","modified":"2024-08-03T23:03:33.527Z","updated_at":"2026-11-02T14:33:05.665371Z"}],"euvd":[{"id":"EUVD-2021-18420","description":"A weak session token authentication bypass vulnerability in Trend Micro IM Security 1.6 and 1.6.5 could allow an remote attacker to guess currently logged-in administrators' session session token in order to gain access to the product's web management interface.","status":"published","published":"2021-05-10T11:00:31Z","modified":"2024-08-03T23:03:33Z","updated_at":"2026-11-03T03:24:38.977347Z"}],"ghsa":[{"id":"GHSA-f4cv-895p-vw62","title":"A weak session token authentication bypass vulnerability in Trend Micro IM Security 1.6 and 1.6.5...","description":"A weak session token authentication bypass vulnerability in Trend Micro IM Security 1.6 and 1.6.5 could allow an remote attacker to guess currently logged-in administrators' session session token in order to gain access to the product's web management interface.","status":"published","published":"2022-05-24T19:01:55Z","modified":"2023-01-29T05:07:35Z","cwes":["CWE-287"],"updated_at":"2026-11-02T14:46:10.663769Z"}],"nvd":[{"id":"CVE-2021-31520","description":"A weak session token authentication bypass vulnerability in Trend Micro IM Security 1.6 and 1.6.5 could allow an remote attacker to guess currently logged-in administrators' session session token in order to gain access to the product's web management interface.","status":"published","published":"2021-05-10T11:15:08.003Z","modified":"2026-06-17T03:51:57.137Z","cvss":[{"version":"3.1","score":8.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":6.8,"vector":"AV:N/AC:M/Au:N/C:P/I:P/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-287"],"updated_at":"2026-11-02T14:06:53.343329Z"}]}}